I can't copy or paste in any application on my MacBook Pro

I was trying to cut a message that I was writing into notes. When I noticed it wouldn't paste. I proceded to work on my school asignment and found that I could not copy and paste anything from google docs into the search box in google chrome. I thought Google chrome might be having trobles so I went to Safari and the same thing happened. Please help. I have A MacBook Pro from Mid 2012. I also just updated to mac os high seirra. Some one please help!!!